CD8A and head and neck squamous cell carcinoma: After CD8+ T cells were incubated with CSC (CD44+) or more differentiated cells (CD44−) isolated from head and neck squamous cell carcinoma (HNSCC), the authors observed that the CD8+ T cells stimulated with CD44+ cells produced less IFNγ when compared to CD44−, showing that CSC present less immunogenicity and this feature favors a scape from the immunologic system [147].